package com.atguigu.springcloud.lb;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author 秦啸
 * @Description
 * @Date 创建于 2020/3/12 8:46
 */
@Component
public class MyLB implements LoadBalancer {

    private AtomicInteger atomicInteger = new AtomicInteger(0);

    public final int getAndIncrement() {
        int current;
        int next;
        do {
            current = this.atomicInteger.get();
            next = current >= 2147483647 ? 0 : current + 1;

        } while (!this.atomicInteger.compareAndSet(current, next));
        System.out.println("*****第几次方位next:" + next);
        return next;
    }


    //负载均衡算法：第几次请求%服务器总数量=实际访问。服务每次启动从1开始
    @Override
    public ServiceInstance instances(List<ServiceInstance> serviceInstances) {
        int index = getAndIncrement();
        return serviceInstances.get(index % serviceInstances.size());
    }
}
